Coating and sizing composition



United Sttes Patent COATING AND SIZING CONIPOSITION Myron E. Calkins, Bay Minette, Ala., and George K. Greminger, 3n, Midland, Mich assignors to The Dow Chemical Company, Midland, Mich., a corporation of Delaware No Drawing. Application July 21, 15951, Serial No. 238,016

2 Claims. (Cl. 106-186) This invention relates to a novel, water soluble sizing composition which provides flexible and strongly adherent coatings and films. The new composition is especially adapted for use as a warp size for its effect during the weaving of fabrics from synthetic yarns.

Warp sizes are usually employed to improve the weaving process. Warp sizes applied to yarn aid in maintaining the original tenacity of the yarn by lubricating the yarn, by reducing abrasion during weaving, and by laying the loose filaments or fiber ends of the yarn. Furthermore, a yarn that has been coated with an effective sizing composition exhibits good clean breaks when pulled apart under weaving tension. In contrast, a yarn with an ineffective sizing composition exhibits a fluffy mass of fibers at the broken ends of the yarn protruding from the fabric.

Many substances such as vegetable and mineral oils, aqueous solutions of gelatine and starch, glycerin, and certain natural gums, waxes and fatty acids have been used as warp sizes. While these substances have resulted in some improvement in the yarns, they still left much to be desired, for they would not always function evenly and smoothly due to uneven penetration into the yarns treated or difficulty in applying them uniformly. This is especially true when sizing synthetic yarns whose surface texture is smoother and less absorbent than natural fibers.

It is an object of the present invention to provide a novel, water soluble sizing composition which is strongly adherent to surfaces of yarn and is capable of even and uniform penetration of both synthetic and natural yarns to form a flexible coating thereon.

In fulfillment of the above object the present invention comprises an aqueous methyl cellulose composition containing, as plasticizer, N-acetylethanolamine. A mixture of from 25 to 90 and preferably 75 to 85 per cent by weight of methyl cellulose may be employed with 75 to 10 and preferably 25 to 15 per cent of N-acetylethanolamine as the solute in the composition. About 5 to 15 and preferably 9 to 10 per cent by Weight of the mixture is dissolved in water to make the sizing composition. Any water-soluble methyl cellulose may be employed, but for convenience in preparing the solution, a methyl cellulose is preferred whose specific viscosity at 20 C. ranges from 10 to 25 centipoises as measured on 2 per cent solutions in Water. If desired, a wetting agent such as an alkylated aryl polyether-alcohol or the dioctyl ester of sodium sulfosuccinic acid may be added in an amount of at least 0.05 per cent by weight of the total composition, to aid in spreading and penetration. Defoamers, such as tributyl phosphate or lauryl alcohol, and water-soluble lubricants may also be added, but their presence is not critical to the composition of the present invention. The new sizing composition exhibits outstanding adhesion and lubrication when applied to any synthetic yarn. Nylon, cellulose acetate, acrylonitrile copolymer and vinyl chloride copolymer fibers are a few examples of synthetic yarn which exhibit improved properties when sized with the new composition.

Example A sizing composition consisting of: 86.9 per cent by weight of water 0.1Xp1e60;:ent alkylated aryl polyether alcohol (Triton 13 per cent solids:

50% N-acetylethanolamine 2,697,666 Patented Dec. 21, 1954 "ice was prepared by mixing the wetting agent and the N- acetylethanolamine with the water, and then adding the methyl cellulose. The sizing composition so formed was employed for treating yarn in a commercial two roll padder so that about 3 to 17 per cent by weight of the size, varying with the type of yarn, was applied to the yarn, on a dry basis. The size was applied to vinyl polymer yarns such as Dynel and Pinyon, adipic acid-hexamethylene diamine condensation polymer yarn such as nylon, and a cellulose acetate yarn. Samples of each of the sized yarns exhibited aconsistently good adhesion between the yarn and the sizing, and an effective lay-down of surface fuzz on the yarn.

A comparative study was made in which the composition of the present invention and three other commercially available sizing compositions were used as warp sizes on samples of a vinyl chloride copolymer yarn. A photograph was taken of the samples of treated yarn. The photograph clearly indicated a superiority in fiber lay down of the yarn treated by the new composition as compared to the fibers treated otherwise. The yarn treated with the composition of the present invention was clean, with comparatively little fuzz or fibers protruding from the surface of the yarn. it also had the smooth feeling and stiffness of a well sized yarn. Furthermore, on breaking the yarn, treated by the new composition, its broken ends were neat and clean with no protruding fibers. In contrast, the samples of yarn treated by the three commercial sizing compositions all exhibited many loose and protruding fiber ends, and, when broken, they formed unsightly terminal flares.

The function of N-acetylethanolamine in the composition of the present invention is unique, as otherwise similar sizing compositions, using other amines in place of N-acetylethanolamine, have shown inferior results. Triethanolamine, diethanolamine, diethanoltnonoisopropanolamine, monoethanol diisopropanolamine, aminoethylethanolamine, and monoethylisopropanolamine are examples of amines tested in place of N-acetylethanolamine, whose compositions with methyl cellulose were generally found to exhibit poor adhesion and flexibility when applied to the various yarns.

To improve adhesion to some of the synthetic yarns, various acidic additives were tested in the new composition in amounts of about 0.5 to 2 per cent by weight of the total composition. These included gluconic, boric, acetic, malonic, and lactic acids. The most outstanding coating properties were observed when the composition of the present invention contained gluconic acid and was applied to yarn of the nylon type (adipic acid-hexamethylene diamine condensation polymer).

The new composition has been described as a Warp size, for use in weaving. It is equally useful when employed to size the yarn used in knitting.

It is an interesting observation that films cast from aqueous solutions of the new composition have elongation values comparable with those of the various commercial synthetic yarns. This may explain part of the outstanding utility of the composition as a warp size.

We claim:

1. A coating and sizing composition which consists essentially of about 5 to 15 per cent by weight of a mixture consisting of 25 to 90 per cent by weight of water-soluble methyl cellulose and 75 to 10 per cent of N-acetylethanolamine, dissolved in water.

2. A coating and sizing composition which consists essentially of about 10 per cent by weight of a mixture consisting of 75 to per cent by weight of water-soluble methyl cellulose and 25 to 15 per cent of N-acetylethanolamine, dissolved in Water.

References Cited in the file of this patent UNITED STATES PATENTS Number 

1. A COATING AND SIZING COMPOSITION WHICH CONSISTS ESSENTIALLY OF ABOUT 5 TO 15 PER CENT BY WEIGHT OF A MIXTURE CONSISTING OF 25 TO 90 PER CENT BY WEIGHT OF WATER-SOLUBLE METHYL CELLULOSE AND 75 TO 10 PER CENT OF N-ACETYLETHANOLAMINE, DISSOLVED IN WATER. 